Clamping drill fixture



Aug. 5, 1930. o. 1-1. SIEWEK CLAMPING DRILL FIXTURE F iled March 5. 1927 INVENTOR! Otto Iii. Sieuei'.

Patented Aug. 5, 1930 PATENT OFFICE OTTO H. SIEWEK, OF DETROIT, MICHIGAN CLAMPING DRILL FIXTURE Application filed- March 5,

My invention relates to a new and useful improvement in. a clamping drill fixture adapted for clamping a workpiece in position so that the same may be retained firmly locked for various operations, such as drilling, reaming, boring, etc. 7

It is an object of the present invention to provide a clamping fixture of this class in which the workpiece will be held firmly in position and which may be easily and simply operated to 'release the workpiece for removal therefrom and for replacement by another workpiece.

Another object of the invention is the provision in a clamping device of this class of a resiliently held clamping member so that there is a certain amount of yieldability in the clamping parts.

Another object of the invention is the provision in'a clamping fixture of this kind of a cam operated mechanism for moving one of the clamping elements into engaging position with the workpiece provided with a spring member which is compressed when the clamping fixture is in operative position.

.Other objects will appear hereinafter.

The invention consists in the combination and arrangement of parts hereinafter described and claimed.

The invention will be best understood by a reference to the accompanying drawings which form a part of this specification and in which, I

Fig. 1 is a side elevational view of the invention with a part broken away and .a part shown in section.

Fig. 2 is a fragmentary top plan view of the invention. 1 I j Fig. 3 is a sectionaliview taken on substantially line 3-3 of Fig. 2.

. In the invention 1 provide a base 7 projecting upwardly from which at opposite sides are bosses 8 and '9. The mechanism connected'with each of the bosses is the same so that a description of one side of the device will suffice as a description for both sides.

Pressed into the boss 9 is a guide sleeve or Cbushing 10 in which is slidably mounted a shaft 11 having a reduced portion 12 adjacent its upper-end,-about which is positioned in 1927. S rial No. 172,960.

embracing relation, a coil spring 13 engaging at one end a shoulder 13' formed on the bushing 10, and at its other end, a washer 15 which is held in position by the nuts 14 which are threaded on the reduced portion 12. A cover .cap 16 is threaded on the upper end of the bushing or guide sleeve 10 and serves as a lock nut for the nut 17 which is threaded on the bushing 10, this nut engagingthe upper surface of a clamping jaw 18 which is p0- sitioned about the guide sleeve or bushing 10, and engaging at its lower surface the shoulder 29. The clamping jaw 18 is provided on its upper surface with a reinforcing bead or flange 18. Mounted on the lower end of the shaft 11 is a head 19 having a groove 19' formed therein in which engages the cam 20 which. is mounted on-the shaft 21, this shaft 21 being journalled in the base 7 and provided at one end with the retaining collar 22 and at its opposite end with the crank 23 having the handle 24 projecting outwardly therefrom. i H Formed in the clamping jaw or shelf 18 are openings 25 properly located, dependent upon the class of work to be done, and into each of which is, pressed a liner bushing 26 carrying a guide bushing 27..

In operation the workpiece 28 is positioned on the base? .and the shaft 21 rotated by means of the handle 24. As thecam 20 is rotated in the head 19 the shaft 11 will be moved downwardly to carry the jaw or shelf 18 into clamping relation with the workpiece 28, thus clamping the workpiece securely against the base 7. As this movement is effected the spring 13 is compressed and the shaft 21 rocked sufficiently to effect the de- I sired clamping, this desired clamping being effected just as the cam 20 approaches a dead center. A slight further rotation of the I shaft 21 will move the cam 20 beyond center,

the spring 13 thus serving, on account of its tendency to move the shaft 11 upwardly. to lock'the jaw or clamping shelf 18 against the workpiece 28, the crank 23 engaging the base 7andpreventin g further rotation of the shaft 21. hen a workpiece is clamped in a clamping fixture of this kind, it is securely held in position and may be readily released,

col

in reasonable limits by a too tight clamping,

as the spring 13 will take up for such excessive strain as might be exerted upon the clamping jaw 18 were the device to be rigid. Furthermore. a clamping of the workpiece in this manner is quite desirable as a loosening of the workpiece during an operation is prevented.

While I have illustrated and described the preferred form of my invention, I do not 715A. to limit myself to the precise details of structure shown, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A clamping fixture of the class described, comprising: a base; a cam rotatably mounted in said base; a boss projecting upwardly from said base having a bore formed therein registering with said cam; a bushing slidably mounted in said boss; a shaft projected through said bushing and slidable therein; a head on said shaft embracing said cam, said cam being rotatable in said head and engagingthe inner surface thereof; a spring embracing said shaft, the end of said spring adjacent said head engaging shoulders formed in said bushing; an engagement member carried by said shaft and engaging the opposite end of said spring; and a clamping arm projecting outwardly from said bush- 2. A clamping fixture of the class described, comprising: a base; a boss projecting upwardly from said base and having a bore formed therein; a bushing slidably mounted "in said boss and provided, in its bore, intermediate its ends with an internal shoulder; a shaft slidably positioned in said bushing; a head on said shaft below the end of said bushing; an engagement member on the upper end of said shaft; a clamping arm projecting laterally outwardly from said bushing; andresilient means embracing said shaft and engaging, at one end. said engagement member and, at the opposite end, said shoulder and adapted for transmitting downward pressure on said bushing upon movement of said shaft axially in one direction and cam means for movin said shaft axially.

3. A clamping Xture of the class described, comprising: a base; a boss projecting upwardly from said base and having a bore formed therein; a bushing slidably mounted in said boss and provided, in its bore, intermediate its ends with an internal shoulder; a shaft slidably positioned in said bushing; a head on said shaft below the end of said bushing; an engagement-member on the upper end of said shaft; a clamping arm projecting laterally outwardly from said bushing ;'resilient means embracing said shaft and engaging, at one end, said engagement member and, at the opposite end, said shoulder and adapted for transmitting downward pressure on said bushing upon movement of said shaft axially in one direction; and a rotatable cam engaging said head and adapt ed, upon rotation, for reciprocating said shaft. v

4. A clamping fixture of the class described, comprising a base; a horizontally extended shaft rotatably mounted on said'hase; a cam fixedly mounted on said shaft; a vertically extending shaft projecting upwardly of said base: a head on said shaft having a recess herein for reception of said cam, said cam be ng positioned in the axis of said shaft; a clamping arm; means attached to said clamping arm and projected slidably downwardly through an opening in said base, said means having an opening formed therein 9 for reception of said shaft in slidable relation thereto; a spring embracing said shaft positioned Within said means and transmitting pressure to said means upon axial movement of said shaft.

A clamping fixture of the class described, comprising: a base, having an opening formed therein; a bushing slidably engaging in said opening and having a shoulder formed in its bore; a shaft slidably positioned in said bushing and projecting into said base; a head on said shaft below the end of said bushing; an engagement member on the upper end of said shaft; a clamping arm projecting laterally outwardly from said bushing; and resilient means embracing said shaft and engaging at one end, said engagement member and, at the opposite end. said shoulder, and adapted. for transmitting down ward pressure on said bushing, upon movement of said shaft axially in one direction; and rotatable means for naming said shaft axially.

In testimony whereof I have signed the foregoing specification.

OTTO H. SIEWEK. 

